Created on 2020-07-25.00:00:00 last changed 1 week ago
This issue is resolved by the resolution of issue 3460.
The issue is related to LWG 3460.Because the coroutine_handle<> base subobject of a coroutine_handle<P1> can be assigned from the one of a coroutine_handle<P2>, a coroutine_handle<P1> may refer to a coroutine whose promise type is P2. If a coroutine_handle<P> refers to a coroutine with difference, a call to promise() should result in undefined behavior IMO. I think that [coroutine.handle.promise]/1 should be changed to: "Preconditions: *this refers to a coroutine whose promise type is Promise.", and the same precondition should be added to [coroutine.handle.noop.promise], and hence noexcept should be removed from coroutine_handle<noop_coroutine_promise>::promise.
Previous resolution [SUPERSEDED]:
This wording is relative to N4861.
Modify [coroutine.handle.promise] as indicated:Promise& promise() const;
-1- Preconditions: *this refers to a coroutine .-2- Returns: A reference to the promise of the coroutine.
Modify [coroutine.handle.noop], class coroutine_handle<noop_coroutine_promise> synopsis, as indicated:[…] // [coroutine.handle.noop.promise], promise access noop_coroutine_promise& promise() const
Modify [coroutine.handle.noop.promise] as indicated:noop_coroutine_promise& promise() const
-1- Returns: A reference to the promise object associated with this coroutine handle.
|2020-07-26 14:33:55||admin||set||messages: + msg11417|